Objective:
1) Identify mechanisms and develop tools and methods to improve growth efficiency of catfish.
Sub-objective: Development and use of markers for improved fillet yield.
2) Determine mechanisms of host-pathogen interactions and sources of variation in catfish immune function to improve catfish health and survival.
3) Improve efficiency of channel and blue catfish reproduction and channel x blue hybrid production.
4) Identify genomic regions affecting variation in traits of economic importance through quantitative trait locus (QTL) discovery and fine mapping strategies.
Sub-objective: Selective breeding of blue catfish for production of hybrids.
5) Develop, and transfer to commercial producers, channel catfish and blue catfish germplasm improved for growth, yield, and disease resistance for improved production of channel, blue and hybrid catfish.
Sub-objective: Improvement of production practices to increase efficiency and yield.

Approach:
To attain the first objective, we will correlate mitochondrial functional variation with catfish feed efficiency and identify and determine the role of specific genes and gene products (peptides and proteins) involved in controlling growth in catfish. For the second objective, we will construct a catfish microarray targeted toward immune function, characterize functional genetic variation in resistant vs. susceptible channel catfish, and characterize the effect of prebiotic administration on catfish immune function. For the third objective we will induce early maturation in channel catfish and blue catfish through compressed annual temperature cycles, increase ovulation and fertilization efficiency for production of blue X channel F1 hybrid catfish, and establish a technique for spematogonial transplantation between blue and channel catfish. For the fourth objective we will enhance and integrate genetic and physical maps, and identify quantitative trait loci associated with superior production traits, especially carcass traits and survivability to E. ictaluri infection. For the fifth objective, we will produce a line of select channel catfish based on multi-trait selection within a commercial composite population, produce a line of select blue catfish based on males that produce hybrid offspring with superior growth and carcass yield, and produce male channel and blue catfish which have a YY sex chromosome complement for all male catfish production.